Tag: air knife selection

Super Air Knife, Standard Air Knife, Full-Flow Air Knife: What’s the Difference?

Published on by Tyler DanielLeave a comment

EXAIR is THE industry leader when it comes to compressed air operated Air Knives. If you’ve taken a look at our offering, you might ask “what in the world is the difference between the Super, Standard, and Full-Flow Air Knives?”. Fret not, I’m here to clear up any doubts right here on the EXAIR Blog.

Leading the pack is the award-winning Super Air Knife. The Super Air Knife is available (from stock) in aluminum, Type 303 & Type 316 stainless steel, as well as in PVDF with Hastelloy bolts for extremely corrosive applications. The Super Air Knives are offered in lengths ranging from 3”-108” in both aluminum and SS and from 3”-54” for the PVDF knives. Our quietest (just 69 dBA at 80 PSIG) and most efficient knife (2.9 SCFM/inch) offered by EXAIR, the Super Air Knife, is the newest of the bunch. Not only does the knife consume less air than both the Standard or Full-Flow, but it also entrains more ambient air. The Super Air Knife provides ambient air entrainment at a rate of 40:1 (compared to 30:1 on the others). Also, important to note, is the airflow pattern exits the knife straight from the nozzle outlet. On both our Standard and Full-Flow knives, the air exits perpendicularly to the nozzle.

All Super Air Knives ship from stock with ¼ NPT air inlets and ¼-20 tapped holes along the bottom that can be used for mounting. ¼ NPT air inlets are available at either end as well as along the bottom of the knife. Unfortunately, that isn’t always going to work for every application, so we also manufacture specials with custom air inlets as well as additional mounting holes to fit right onto any custom bracket. Both the length of the knife and the airflow length are the same when it comes to the Super Air Knife.

Next is our Standard Air Knife. The original Air Knife provided by EXAIR, the Standard Air Knife has been around since the early days. While still an excellent solution, it doesn’t offer as much as the Super Air Knife in terms of mounting options, materials, or sizes. The actual length of the knife for the Standard Air Knives will be 1” longer than the overall airflow width. This is due to the ¼ NPT air inlets located on either side that take up ½” space each. Only the end air inlets are available to supply to the knife, compared to either end and along the bottom for the Super Air Knives. These knives are offered in either aluminum or 303 SS in lengths ranging from 3”-48”.

Standard Air Knife

As mentioned earlier, the Standard Air Knives airflow pattern exits perpendicularly to the nozzle exit. It’s important that this is understood BEFORE planning out the installation. Due to the wind shear produced along the Coanda profile, the Standard Air Knife is a little bit louder than the Super Air Knife coming in at 80 dBA at 80 PSIG.

Finally, we have the Full-Flow Air Knife. A predecessor to the Super Air Knife, the Full-Flow Air Knife was borne out of a need for a solution where both the length of the knife and the airflow width where the same. Prior to the Super Air Knife, this was the only option that was offered that the length of the airflow pattern would match that of the knife itself.

Moving the air inlets from the ends to the center, the Full-Flow Air Knife has different dimensions than the Standard Air Knife. The differences in dimensions allow it to be the “smallest” profile knife offered off-the-shelf (see a prior Custom Air Knife Blog for some examples of some even smaller!). Just as with the Standard Air Knives, the airflow exits perpendicularly to the nozzle outlet. As such, the sound level is also a little bit higher, coming in at 80 dBA.

The same materials are offered as the Standard Air Knives: aluminum and 303 SS. The Full-Flow Air Knife is available in lengths ranging from 3”-36” in stock.

There’s a reason EXAIR is the industry leader in compressed air-operated knives. Don’t just take my word for it, get one in-house and try it out for yourself! All products shown in the catalog in stock are available with our Unconditional 30-Day Guarantee. If you’re unhappy with the performance for any reason, we’ll arrange for full credit on the original invoice once returned within the first month.

Tyler Daniel, CCASS

Application Engineer

E-mail: TylerDaniel@EXAIR.com

Twitter: @EXAIR_TD

Factors in Selecting an Air Knife – Size, Materials, Stock Levels, Accessories

Published on by John BallLeave a comment

Super Air Knife Family

EXAIR has been manufacturing Intelligent Compressed Air® products since 1983.  In the beginning, the Standard Air Knives and Full Flow Air Knives were very effective at that time.  But as leaders in this market, EXAIR did not want to stop there.  We were able to engineer a more efficient, more powerful, and much safer air knife, the Super Air Knife.  In this blog, I will discuss the features and benefits that the Super Air Knives can offer.

Bernoulli’s principle explains how a high velocity fluid can generate a low pressure.  The EXAIR Super Air Knife creates a high velocity air stream to produce a low pressure to entrain ambient air.   What does this mean for you?  It will save you much money by using less compressed air.  The mass of the ambient air is added into the air stream to give a strong blowing force.  The Super Air Knife has an amplification ratio of 40:1. For every 1 part of compressed air, 40 parts of ambient air is drawn into the blowing air stream.  Ambient air is free, and compressed air is expensive.  EXAIR was able to engineer a design to use the Bernoulli’s principle to make one of the most efficient air knives in the market place.

EXAIR Super Air Knife model 1100108

What else makes EXAIR unchallenged?  We manufacture and stock the widest range in lengths and materials.  To start, EXAIR has Super Air Knives ranging from 3” to 108” (76mm to 2,743mm) in three different materials; aluminum, 303 stainless steel, and 316/316L stainless steel.  There is no-one else in this industry that can manufacture to those lengths.  EXAIR also offers Super Air Knives in PVDF material with Hastelloy hardware for chemical resistant applications from 3” to 54” (76mm to 1,372mm).  Depending on the temperature requirement, chemical resistance, OSHA and FDA regulations, or application details, we probably will have one on the shelf for you.  If EXAIR does not have it, we can make special air knives in different lengths and materials to best fit your application.

Some interesting features for the Super Air Knives are as follows.  They have a compact design that can fit into tight places for blowing and cooling.  The footprint is very small compared to blower-air knife system.  They do not have any moving parts to wear or maintenance to do.  They only need clean compressed air to work.  They blow a laminar air stream which reduces noise levels and create a consistent force along the entire length.  An even force will give you tighter control for blowing applications which will cut compressed air usage unlike the inconsistent and turbulent air flows caused by drilled pipes.

To adjust the force and air usage, this can be easily controlled with a regulator.  The advantage that EXAIR Super Air Knives have is the replaceable shims.  So, you can increase or decrease the gap to get a variety of force ratings.  The Aluminum version uses colored plastic shims for visual verification.  They come stock with a 0.002” (0.05mm) red shim installed.  We have other thicknesses in our Shim Sets which includes a 0.001” (0.03mm), 0.003” (0.08mm), and a 0.004” (0.10mm) colored as amber, green, and tan respectively.  The Stainless Steel Super Air Knives come with a stainless steel shim for higher temperatures and chemical resistance.  Stock units have the 0.002” (0.05mm) thickness as well.  The Shim Sets come with three additional 0.002” (0.05mm) shims to stack.  Similarly, the PVDF Super Air Knives use a PTFE shim for maximum chemical resistance.  It is also 0.002” (0.05mm) thick, and there are three more shims in the Shim Set.  This unique feature of using shims allows for the most flexibility in creating forces for different applications ranging from a blast to remove rocks from a conveyor to a breeze for light duty work.

Super Air Knife Kit

We also offer the Super Air Knives in kits as a more complete system.  The kit includes a filter, regulator and the above-mentioned Shim Set.  The filter removes the debris and water from the compressed air line to optimize the performance of the air knife as well as keeping your product clean.  The regulator is used to make the “fine” adjustment to the blowing force while the shim set is used as the “coarse” adjustment.  EXAIR sells this kit as one model number for simple ordering, and the accessories are properly sized to not hinder the performance of the Super Air Knife.

To optimize the system even more, EXAIR offers a Deluxe Kit for the Aluminum and Stainless Steel models.  This includes the accessories in the kit above, plus an Electronic Flow Control, or EFC.  This exclusive instrument uses a photoelectric eye to start a timing sequence to control a solenoid valve.  So, when a part is not in front of the Super Air Knife for cleaning or cooling, the compressed air is turned off.  This will save you even more money and maximize your efficiency to only blow air when needed.

Plumbing Kits

For the longer Super Air Knives, EXAIR can install a Plumbing Kit, or PKI, to help attach your compressed air to the Air Knife.  They are designed to help lessen the time for install as well as to properly supply compressed air equally along the entire length, specifically for 24” (610mm) and longer.  We can offer the Plumbing Kit separately if you find that it could benefit your fabricators during installation.  EXAIR also offers a Coupling Kit for the Aluminum and Stainless Steel versions.  If you need to extend past the 108” (2,743 mm) width, the Coupling Kit is designed to mount Super Air Knives together at the ends.  You will still get that consistent blowing force along the multiple of Air Knives.  Another helpful accessory is the Universal Air Knife Mounting System.  It has a bracket and an articulated arm that can reach up to 30” (762mm).  With this system, you can position your air knife securely and precisely in any orientation.  It attaches easily to your Super Air Knife and gives you the flexibility to maximize the blowing effect at your target.

Universal Mounting System

With the today’s cost in making compressed air, it is important to use it as efficiently as possible.  The Standard and Full Flow Air Knives would be good options to use.  But the best way to conserve is with the Super Air Knife.  If you have any questions about the Super Air Knife or if you would like to discuss an application, you can contact an Application Engineer at EXAIR.   We will be glad to help you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb